Letting off Some Steam

We like cars. We like to make things. We like speed. So naturally our homegrown downhill coaster club is very popular. The restrictions? The heavy-duty 10" groove tread tire and a $50 spending limit. And the only rule is to make it to the bottom first any way you can (no motors, rockets, rubber bands, pedals, wind sails, flubber, or gerbils). See you on the track.